Inductor on microelectronic die

Abstract

A microelectronic device comprises: a die; a first metal column over a first bond pad of the die; a first metal strip over the die; a second metal column over the first metal strip; and a second metal strip over the first and second metal columns and over the die, in which the second metal strip has a pair of bent segments and a first segment coupled between the pair of bent segments.

What is claimed is: 
     
         1 . A microelectronic device, comprising:
 a die;   a first metal column over a first bond pad of the die;   a first metal strip over the die;   a second metal column over the first metal strip; and   a second metal strip over the first and second metal columns and over the die, in which the second metal strip has a pair of bent segments and a first segment coupled between the pair of bent segments.   
     
     
         2 . The microelectronic device of  claim 1 , further comprising:
 a third metal column over the first metal strip or on the die;   a fourth metal column over a second bond pad of the die; and   a third metal strip over the third and fourth metal columns and over the die, in which the third metal strip has a second pair of bent segments and a second segment coupled between the second pair of bent segments.   
     
     
         3 . The microelectronic device of  claim 2 , further comprising:
 a seed layer over the die, the seed layer including at least one of: titanium, tungsten, chromium, or nickel,   wherein the first metal strip is over the seed layer.   
     
     
         4 . The microelectronic device of  claim 1 , wherein a thickness of the first metal strip is between 3 microns and 30 microns. 
     
     
         5 . The microelectronic device of  claim 2 , wherein:
 each of the first through fourth metal columns includes copper;   a respective width of each of the first through third metal columns is between 25 microns and 50 microns;   a respective length of each of the first through third metal columns is between 25 microns and 300 microns; and   a respective height of each of the first through third metal columns is between 30 microns and 100 microns.   
     
     
         6 . The microelectronic device of  claim 2 , further comprising:
 a first seed layer over the first metal strip; and   a second seed layer over the first, second, third, and fourth metal columns,   wherein:
 the second metal column and the third metal column are over the first seed layer; 
 the second and third metal strips are over the second seed layer; and 
 each of the first and second seed layers includes at least one of: titanium, chromium, or nickel. 
   
     
     
         7 . The microelectronic device of  claim 2 , wherein the second and third metal strips include copper. 
     
     
         8 . The microelectronic device of  claim 2 , wherein a respective thickness of each of the second and third metal strips is between 3 microns to 30 microns. 
     
     
         9 . The microelectronic device of  claim 2 , further comprising:
 a first layer of die attach material over the second metal strip; and   a second layer of die attach material over the third metal strip,   wherein the die attach material includes at least one of: a solder, or an adhesive.   
     
     
         10 . The microelectronic device of  claim 2 , further comprising:
 a magnetic material around at least parts of the first through third metal strips and at least parts of the first through fourth metal columns.   
     
     
         11 . The microelectronic device of  claim 10 , wherein the magnetic material includes magnetic particles, and a molding compound in which the magnetic particles are suspended. 
     
     
         12 . The microelectronic device of  claim 10 , wherein the first through fourth metal columns and the first through third metal strips are part of an inductor electrically coupled between the first and second bond pads, in which the inductor has a linear configuration. 
     
     
         13 . The microelectronic device of  claim 10 , further comprising a fourth metal strip over the die and between the first and second bond pads,
 wherein the first through fourth metal columns and the first through fourth metal strips are part of an inductor having a toroidal configuration.   
     
     
         14 . The microelectronic device of  claim 2 , further comprising:
 a fifth metal column over a third bond pad of the die; and   a fourth metal strip over the fifth metal column over the die; and   a layer of die attach material over the fourth metal strip.   
     
     
         15 . The microelectronic device of  claim 2 , further comprising:
 a fourth metal strip having a first end over a third bond pad on the die;   a fifth metal column over a second end of the fourth metal strip, the second end being opposite to the first end; and   a layer of die attach material over the fifth metal column, in which the fifth metal column is between the layer of die attach material and the fourth metal strip.   
     
     
         16 . A microelectronic device, comprising:
 a die; and   an inductor coupled to the die, in which the inductor includes:
 a first metal pillar; 
 a first metal strip, in which the first metal strip has a first pair of bent segments and a first segment coupled between the first pair of bent segments; 
 a second metal pillar over one of the first pair of bent segments of the first metal strip; and 
 a second metal strip having a second pair of bent segments and a second segment coupled between the second pair of bent segments, in which the second pair of bent segments are over the first and second metal pillars, and the first and second metal pillars support the second metal strip over the die. 
   
     
     
         17 . The microelectronic device of  claim 16 , further comprising a magnetic material surrounding at least a part of the inductor. 
     
     
         18 . The microelectronic device of  claim 16 , wherein the first and second metal strips include copper. 
     
     
         19 . The microelectronic device of  claim 16 , further comprising a seed layer coupled between the first metal strip and the surface, the seed layer including at least one of: titanium, tungsten, chromium, or nickel. 
     
     
         20 . The microelectronic device of  claim 16 , wherein the first segment is angled from the second segment.